Katherine S. Forsyth is a Scottish historian who specializes in the history and culture of Celtic-speaking peoples during the 1st millennium AD, in particular the Picts. She is currently a professor in Celtic and Gaelic at the University of Glasgow in Scotland.
Forsyth is an expert in the Ogham script, and has provided readings for a number of Ogham inscriptions, including the Buckquoy spindle-whorl and the Lunnasting stone. Forsyth has reinterpreted a number of Pictish Ogham stone inscriptions that were previously thought to be written in an unknown pre-Indo-European language, and has argued that the Picts spoke a Brythonic language.
- 1995. "The ogham-inscribed spindle-whorl from Buckquoy: evidence for the Irish language in pre-Viking Orkney?". In Proceedings of the Society of Antiquaries of Scotland 125: 677–696.
- 1995. "Language in Pictland: spoken and written". In Nicoll, E.H. and Forsyth, K. (eds.), A Pictish Panorama: the story of the Picts. Pinkfoot Press. ISBN 1-874012-10-5
- 1995. "Some thoughts on Pictish symbols as a formal writing system". In Henderson, I. and Henry, D. (eds.), The Worm, the Germ and the Thorn: Pictish and Related Studies Presented to Isabel Henderson. Pinkfoot Press. ISBN 1-874012-17-2
- 1997. Language in Pictland: the case against 'non-Indo-European Pictish. Studia Hameliana, 2. Utrecht: De Keltiche Draak ISBN 90-802785-5-6
- 2001. Okasha, E. and Forsyth, K., Early Christian inscriptions of Munster: a corpus of the inscribed stones. Cork: Cork University Press. ISBN 978-1-85918-170-6
- 2005. "HIC MEMORIA PERPETUA: the inscribed stones of sub-Roman southern Scotland". In: Foster, S.M. and Cross, M. (eds.) Able Minds and Practised Hands: Scotland's Early Medieval Sculpture in the Twenty-First Century. Society for Medieval Archaeology Monograph Series (23). Society for Medieval Archaeology. ISBN 978-1-904350-74-3
- 2007. "An ogham-inscribed plaque from Bornais, South Uist". In Ballin-Smith, B., Taylor, S. and Williams, G. (eds.), West over Sea: Studies in Scandinavian Sea-Borne Expansion and Settlement Before 1300. Leiden: Brill. ISBN 978-90-04-15893-1
- 2008. Forsyth, K. (ed.), Studies on the Book of Deer. Dublin: Four Courts Press. ISBN 978-1-85182-569-1
- 2011. Barrowman, R.C. and Forsyth, K., "An Ogham-Inscribed Slab from St Ninian’s Isle, Found in 1876". In The Chapel and Burial Ground on St Ninian’s Isle, Shetland. Excavations Past and Present. Society for Medieval Archaeology.
- Forsyth (1995)
- Forsyth (1997)
- Forsyth, Katherine (1997), Language in Pictland: the case against 'non-Indo-European Pictish', vol. 2, Utrecht: De Keltiche Draak, ISBN 9789080278554, retrieved 21 April 2022
- Forsyth, Katherine (1995), "The ogham-inscribed spindle-whorl from Buckquoy: evidence for the Irish language in pre-Viking Orkney?" (PDF), Proceedings of the Society of Antiquaries of Scotland, 125: 677–696, retrieved 24 July 2015